Image reading apparatus, image forming apparatus and image forming system

ABSTRACT

An image reading apparatus  300  comprises: the scanner device SD which reads information about a sheet P conveyed on a paper conveying route PP and information about a position, a form and a color of an image formed on the sheet P; a spectrophotometer CI which reads information about a color of an image formed on a sheet P conveyed on the paper conveying route PP; and a support base TR which incorporates the paper conveying route and a motor for conveying a sheet and can be pulled out from a main body together with the paper conveying route and the motor. The scanner device SD is not mounted on the support base TR but fixed to the main body of the image reading apparatus. The spectrophotometer CI is mounted on and fixed to the support base TR, and spaced from the paper transfer route PP by a predetermined distance.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 toJapanese Patent Application No. P2016-126255, filed Jun. 27, 2016. Thecontents of this application are herein incorporated by reference intheir entirety.

BACKGROUND OF THE INVENTION Field of Invention

The present invention relates to an image reading apparatus, an imageforming apparatus and an image forming system.

Description of Related Art

Heretofore, an image reading apparatus is proposed in which it ispossible to pull out an image reading unit for reading an original imagein the horizontal direction, or pull out some constituents of the imagereading apparatus in the horizontal direction so that an image readingunit can be removed. In the case of such an image reading apparatus, bythe above drawer-type structure, it is possible to easily perform jamhandling, checkup and replacement of specific parts, maintenance and thelike (for example, refer to Japanese Patent Published Application No.2015-226084 and Japanese Patent Published Application No. 2014-45301).

In the image reading apparatus, the image reading unit for readinginformation from an original or a printed sheet may be a unit which hasto be installed with a higher positional accuracy in relation to a paperconveying route, a unit which has to be installed in a position to whichvibration is hardly transmitted from a motor which drives conveyancerollers and the like installed on the paper conveying route, and thelike unit.

However, in the case of the above conventional image reading apparatus,it is not taken into consideration what location an image reading unitshould be installed in. Because of this, a positional accuracy may bereduced by installing an image reading unit, which has to be installedwith a higher positional accuracy, in order that the image reading unitcan be pulled out. Also, an image reading unit which has to be installedin a position to which vibration is hardly transmitted from a motor, maybe installed in a position to which vibration is easily transmitted froma motor. Particularly, in the case of an image reading apparatusprovided with a drawer-type structure and a plurality of image readingunits, because of its complicated structure and limited availableinstallation space, it becomes difficult to optimize an installationarrangement of the plurality of image reading units.

Incidentally, this is a common problem not only for an image readingapparatus but also for an image forming apparatus and an image formingsystem which incorporates the image reading apparatus.

SUMMARY OF THE INVENTION

To achieve at least one of the above-mentioned objects, reflecting oneaspect of the present invention, an image reading apparatus comprises: afirst image reading unit which reads information about a sheet conveyedon a paper conveying route and information about a position, a form anda color of an image formed on the sheet; a second image reading unitwhich reads information about a color of an image formed on a sheetconveyed on the paper conveying route; a support base which incorporatesthe paper conveying route and a motor for conveying a sheet and can bepulled out from a main body together with the paper conveying route andthe motor, wherein the first image reading unit is not mounted on thesupport base but fixed to a main body of the image reading apparatus,and wherein the second image reading unit is mounted on the support baseand fixed to the support base in a position spaced from the papertransfer route by a predetermined distance.

Also, to achieve at least one of the above-mentioned objects, reflectingone aspect of the present invention, an image forming apparatus forms animage on a sheet and incorporates an image reading apparatus comprising:a first image reading unit which reads information about a sheetconveyed on a paper conveying route and information about a position, aform and a color of an image formed on the sheet; a second image readingunit which reads information about a color of an image formed on a sheetconveyed on the paper conveying route; a support base which incorporatesthe paper conveying route and a motor for conveying a sheet and can bepulled out from a main body together with the paper conveying route andthe motor, wherein the first image reading unit is not mounted on thesupport base but fixed to a main body of the image reading apparatus,and wherein the second image reading unit is mounted on the support baseand fixed to the support base in a position spaced from the papertransfer route by a predetermined distance.

Furthermore, to achieve at least one of the above-mentioned objects,reflecting one aspect of the present invention, an image forming systemincludes an image forming apparatus which forms an image on a sheet, andan image reading apparatus comprising: a first image reading unit whichreads information about a sheet conveyed on a paper conveying route andinformation about a position, a form and a color of an image formed onthe sheet; a second image reading unit which reads information about acolor of an image formed on a sheet conveyed on the paper conveyingroute; a support base which incorporates the paper conveying route and amotor for conveying a sheet and can be pulled out from a main bodytogether with the paper conveying route and the motor, wherein the firstimage reading unit is not mounted on the support base but fixed to amain body of the image reading apparatus, and wherein the second imagereading unit is mounted on the support base and fixed to the supportbase in a position spaced from the paper transfer route by apredetermined distance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration view for schematically showing an example ofan image forming system in accordance with an embodiment of the presentinvention.

FIG. 2 is a configuration view for schematically showing an example ofthe image forming apparatus shown in FIG. 1.

FIG. 3 is a front view for showing an example of an outlineconfiguration of the image reading apparatus shown in FIG. 1.

FIG. 4 is a perspective view for showing an example of an outlineconfiguration of the image reading apparatus shown in FIG. 1.

FIG. 5 is a front view for showing details of a scanner device shown inFIG. 3 and FIG. 4.

FIG. 6 is a schematic perspective view for showing the relationshipbetween a spectrophotometer and an upper guide plate as shown in FIG. 3and FIG. 4.

FIG. 7 is a view for schematically showing the configuration of theupper guide plate, as illustrated in FIG. 6, which is rotating.

FIG. 8 is a view for schematically showing another example of theconfiguration of the upper guide plate, as illustrated in FIG. 6, whichis rotating.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a description is given of embodiments of the presentinvention with reference to the drawings.

FIG. 1 is a configuration view for schematically showing an example ofan image forming system 1 in accordance with an embodiment of thepresent invention. As shown in FIG. 1, the image forming system 1includes a paper feed apparatus 100, an image forming apparatus 200, animage reading apparatus 300 and a discharge unit 400. The paper feedapparatus 100 feeds a sheet P to the image forming apparatus 200. Theimage forming apparatus 200 forms an image on a sheet fed by the paperfeed apparatus 100. The image reading apparatus 300 reads a sheet onwhich an image is formed by the image forming apparatus 200, andperforms various types of processing. The discharge unit 400 is providedwith a catch tray 401, and discharges a sheet P, which is conveyed fromthe image reading apparatus 300, to the catch tray 401.

FIG. 2 is a configuration view for schematically showing an example ofthe image forming apparatus 200 shown in FIG. 1. The image formingapparatus 200 is a tandem color image forming apparatus which includes aplurality of photoreceptor drums vertically arranged in contact with oneintermediate transfer belt to form full-color images. The image formingapparatus 200 is provided with an image reading unit 2 consisting of anautomatic document feeder and a scanning exposing device on top thereof,and an image forming unit 3 and the plurality of paper feed trays 4 at abottom thereof.

The image reading unit 2 conveys an original placed on an original trayof the automatic document feeder by a paper conveying unit, and scansand exposes images formed on both or either side of the original to readimage information. Also, the image reading unit 2 is configured to readimage information of an original which is placed on a contact glass.

The image forming unit 3 receives sheets S supplied from the pluralityof paper feed tray 4. The image forming unit 3 performs an imageformation process on a sheet based on image information read by theimage reading unit 2 or image information transmitted from a PC(Personal Computer) or the like.

The image forming unit 3 is provided with an image transfer unit 3 a anda fixing unit 3 b. The image transfer unit 3 a forms toner images onphotoreceptor units and transfers the toner images to a sheet P by anelectrophotographic process for charging, exposing and developing. Theimage transfer unit 3 a of this embodiment is of a type having anintermediate transfer belt. Toner images on a plurality of thephotoreceptor units are transferred to the intermediate transfer belt.The toner images on the intermediate transfer belt are transferred to asheet P.

The fixing unit 3 b forms a nip portion between a heat roller and apressure roller to convey a sheet P. The fixing unit 3 b applies heatand pressure to the sheet P, while conveying the sheet through the nipportion. Toner melts by heat and pressure and is transferred and fixedto the sheet P as an image.

The image forming apparatus 200 is provided with a sheet reversing route5 extending from the downstream side of the fixing unit 3 b to theupstream side of the image transfer unit 3 a. The sheet reversing route5 is a route for reversing the front and back sides of a sheet P andconveying the sheet P to the image transfer unit 3 a again. This sheetreversing route 5 makes it possible to form image formation on both thefront and back sides of a sheet P.

FIG. 3 is a front view for showing an example of an outlineconfiguration of the image reading apparatus 300 shown in FIG. 1. FIG. 4is a perspective view for showing an example of an outline configurationof the image reading apparatus 300 shown in FIG. 1.

As shown in FIG. 3 and FIG. 4, the image reading apparatus 300 has aframe member FM as a skeleton. The frame member FM is a metal memberwhich consists at least of the sides of a rectangular parallelepipedwhich forms a housing of the image reading apparatus 300. The imagereading apparatus 300 is provided with a scanner device (a first readingunit) SD and a spectrophotometer (a second reading unit) CI. By thisconfiguration, the image reading apparatus 300 reads information of asheet P passing through a paper conveying route PP. Incidentally, thepaper conveying route PP includes a first paper conveying route PP1 anda second paper conveying route PP2. The first paper conveying route PP1is a route on which a sheet P is read by the scanner device SD while thesheet P is conveyed through the route. The second paper conveying routePP2 is a route on which a sheet P is read by the spectrophotometer CIwhile the sheet P is conveyed through the route.

The image reading apparatus 300 is provided with a support base TR whichcan be inserted and extracted in the horizontal direction toward thefront side. The paper conveying route PP and the spectrophotometer CIare mounted on the support base TR. Furthermore, there are mounted amotor M for conveying a sheet P, a first background member BM1 and asecond background member (background member) BM2 on the support base TR.The support base TR is positioned by a first member E1, which isprovided on the frame member FM, when the support base TR is not pulledout, i.e., when the support base TR is inserted into a main body (theapparatus 300 except the support base TR).

The first member E1 is a projecting rod (only two members areillustrated in FIG. 3 and FIG. 4 respectively as the first member E1).The projecting rod is projecting toward the front from the vicinity ofthe middle of each of four vertical sections VP of the frame member FMextending in the vertical direction. Four holes H are formed through thesupport base TR (only two holes H are illustrated in FIG. 4). When thesupport base TR is inserted into the main body, the first members E1which is a projecting rod is engaged with the hole H. The support baseTR can thereby be positioned by this configuration.

The scanner device SD reads information about a sheet P conveyed throughthe first transfer route PP1, and information about the position, formand color of an image formed on the sheet P. Specifically, the scannerdevice SD reads, as information about a sheet P conveyed through thefirst transfer route PP1, outline information of the sheet P. Also, thescanner device SD reads, as information about the position of an image,for example, information about the line segment intersection position ofa cross hair which is formed at each of four corners of a sheet P.

The scanner device SD can determine if an image formation position iscorrect by reading information about the intersection positions.Furthermore, the scanner device SD reads information about line segmentsas information about the form of an image. The scanner device SD candetermine, by reading information about line segments, if the imageformation condition is appropriate, for example, if a line is straight,if the thickness of a line is appropriate, or the like.

This type of the scanner device SD is fixed to the main body side bysecond members E2 which are attached to the frame member FM.Specifically, the second members E2 consist of two plate members PM andtwo connection rods CR. The two plate members PM are attached to anupper front part UFP and an upper rear part URP of the frame member FMrespectively. The two connection rods CR serve to connect between thetwo plate members PM. The scanner device SD is supported and fixed tothe main body side by the two connection rods CR passing through thehousing (symbol CH1 as described below) of the scanner device SD.

Incidentally, the first background member BM1 is located in the oppositeside of the scanner device SD with the first transfer route PP1therebetween. The first background member BM1 serves as a backgroundwhen the scanner device SD reads various information. The firstbackground member BM1 has a profile of a polygon (for example, hexagon)in a front view. The first background member BM1 can be rotated aroundthe central axis “a” located at the center thereof. Colors such as whiteand black are assigned to the faces of the polygonal body of the firstbackground member BM1. When a white-base sheet P is conveyed, the firstbackground member BM1 rotates in order that a black face is directed tothe scanner device SD. When a black-base sheet P is conveyed, the firstbackground member BM1 rotates in order that a white face is directed tothe scanner device SD. The image reading apparatus 300 can therebyeasily detect the surrounding edges of a sheet P with reference to thedifference in brightness between the sheet P and the background.

FIG. 5 is a front view for showing details of the scanner device SDshown in FIG. 3 and FIG. 4. As illustrated in FIG. 5, the scanner deviceSD includes a housing (first housing) CH1 which is formed into anapproximately hook-type shape as seen from the front side. The scannerdevice SD is provided with first to fifth mirrors M1 to M5 (opticalsystem), first and second lens units L1 and L2 (optical system), and aCCD (Charge Coupled Device) line sensor SE.

The first lens unit L1 consists of a lens facing in the first transferroute PP1 side. The first to fifth mirrors M1 to M5 are arranged toreflect light input through the first lens unit L1 and lead the light tothe second lens unit L2 for the purpose of securing a necessary lightpath. The second lens unit L2 images light led by the first to fifthmirrors M1 to M5 on the CCD line sensor SE. The CCD line sensor SE readsvarious information of a sheet P from the imaged light. The informationwhich is read is transmitted to a control unit which is not shown in thefigure. Incidentally, when vibration is applied, optical path deviationmay occurs in the scanner device SD which includes a plurality ofoptical systems and the CCD line sensor SE. The scanner device SD isthereby a read function unit which is preferably protected fromvibration.

Referring to FIG. 3 and FIG. 4 again. The spectrophotometer CI readsinformation about colors of an image formed on a sheet P which isconveyed through the second transfer route PP2. The spectrophotometer CIis highly accurately positioned in relation to the second transfer routePP2. The positioning error is within ±0.2 mm or smaller. Namely, thespectrophotometer CI is fixed to the support base TR in order that thedistance between the spectrophotometer CI and the second transfer routePP2 is within a predetermined design value±0.2 mm. The spectrophotometerCI includes a photometric function unit incorporated in a housing(second housing) CH2 which is approximately rectangular in a front view.The spectrophotometer CI can read colors of an image, for example, bymeasuring intensity of light at each wavelength.

Incidentally, the housing CH2 is arranged to be fitted into thehook-like portion of the housing CH1. In other words, the housing CH1and the housing CH2 approximately form a rectangular in combination asseen from the front side so that the setting space thereof is optimized.

The color information read by the spectrophotometer CI is transmitted toa control unit which is not shown in the figure. The control unitcalibrates colors by comparing color information read by the scannerdevice SD with color information read by the spectrophotometer CI. Afteronce performing this calibration process, it is possible to increase theaccuracy of colorimetrically measurement with the scanner device SD sothat the image reading apparatus 300 can perform accurate colordetection only with the scanner device SD at the time of large volumeprinting.

The second background member BM2 is located in the opposite side of thespectrophotometer CI with the second transfer route PP2 therebetween.The second background member BM2 is fixed to the support base TR in thislocation. When reading colors of images formed on thin paper, because ofthe transparency of the thin paper, the colorimetric measurement resultmay be different from that of images formed on thick paper even with thesame colors. The second background member BM2 is a member for preventingsuch a discrepancy.

The motor M shown in FIG. 3 drives various conveyance roller pairs R1 toR3 for conveying a sheet P. Incidentally, while only one motor M isillustrated in FIG. 3 for the sake of clarity in illustration, aplurality of motors may be used.

The first conveyance roller pair R1 is located in the upstream side ofthe first transfer route PP1. The second conveyance roller pair R2 islocated in the upstream side of the second transfer route PP2. The thirdconveyance roller pair R3 is located in the downstream side of thesecond transfer route PP2. Each of the conveyance roller pairs R1 to R3consists of a drive roller which is driven by the motor M and anon-driven roller which freely rotates.

Furthermore, the second paper conveying route PP2 is provided with apair of guide plates GB. The pair of guide plates GB serve to guideconveyance of a sheet P. The pair of guide plates GB consists of anupper guide plate GB1 and a lower guide plate GB2. These guide platesGB1 and GB2 are arranged approximately in parallel with each other. Thespectrophotometer CI as described above is mounted on the upper guideplate GB1.

FIG. 6 is a schematic perspective view for showing the relationshipbetween the spectrophotometer CI and the upper guide plate GB1 as shownin FIG. 3 and FIG. 4. As shown in FIG. 6, the spectrophotometer CI islocated in the vicinity of the middle of the upper guide plate GB1. Thespectrophotometer CI is not necessarily directly mounted on the upperguide plate GB1, but may be mounted in the vicinity of the middle of theupper guide plate GB1 with another member therebetween.

An opening O1 is formed through the upper guide plate GB1 in a positioncorresponding to the spectrophotometer CI. The reading side (lenssection) of the spectrophotometer CI faces a sheet P side through theopening O1. A rotation axis RA is installed at the rear end of the upperguide plate GB1. The upper guide plate GB1 is thereby capable ofrotating around the rotation axis RA.

FIG. 7 is a view for schematically showing the configuration of theupper guide plate GB1, as illustrated in FIG. 6, which is rotating. Asshown in FIG. 7, the upper guide plate GB1 is capable of rotating upwardaround the rotation axis RA at the rear end. Because of this, the pairof guide plates GB are configured in order that the relative positionalrelationship between the upper guide plate GB1 and the lower guide plateGB2 can be changed. The pair of guide plates GB are configured to exposeat least part of the inner surface IS of the pair of guide plates GB inorder to prevent jam handling from being difficult. Namely, in the imagereading apparatus 300, the spectrophotometer CI and the support base TRare integrated. Because of this, even if the support base TR is pulledout, jam handling may become difficult on the second transfer route PP2due to presence of the spectrophotometer CI. However, such difficulty isresolved by making it possible to change the relative positionalrelationship of the pair of guide plates GB.

Incidentally, the expression “expose at least part” in the abovedescription means that the relative positional relationship of the pairof guide plates GB is changed so that at least part of the inner side ISof one guide plate GB is no longer located in the opposed position tothe inner side IS of the other guide plate GB. As shown in FIG. 7, anopening O2 is formed through the lower guide plate GB2 in a positioncorresponding to the second background member BM2. The second backgroundmember BM2 can face the sheet P side through the opening O2.

Furthermore, as shown in FIG. 3 and FIG. 4, the pair of guide plates GBare arranged to cover the reading side of the spectrophotometer CI andthe second background member BM2. This structure “arranged to cover”means that the opposed position to the reading side of thespectrophotometer CI corresponds to the installation area where thelower guide plate GB2 exists and the opposed position to the secondbackground member BM2 corresponds to the installation area where theupper guide plate GB1 exists. When the relative positional relationshipof the pair of guide plates GB is changed, as has been discussed above,it is preferred that the reading side of the spectrophotometer CI andthe second background member BM2 are exposed. The maintainability of thespectrophotometer CI and the second background member BM2 can thereby beimproved. In this case, this “exposed” structure means that the opposedposition to the reading side of the spectrophotometer CI becomes out ofthe installation area where the lower guide plate GB2 exists and theopposed position to the second background member BM2 becomes out of theinstallation area where the upper guide plate GB1 exists.

FIG. 8 is a view for schematically showing another example of theconfiguration of the upper guide plate GB1, as illustrated in FIG. 6,which is rotating. The upper guide plate GB1 is not necessarily designedto be capable of rotating around the rotation axis RA at the rear end.For example, as illustrated in FIG. 8, the rotation axis RA of the upperguide plate GB1 may be located in a slightly front side of the center ofthe upper guide plate GB1 (in the front side of the spectrophotometerCI). It is therefore possible to rotate, of the upper guide plate GB1,only the portion located in the front side of the spectrophotometer CIaround the rotation axis RA.

Meanwhile, in the example shown in FIG. 8, it is possible to expose atleast part of the inner surface IS of the pair of guide plates GB bymaking it possible to change the relative positional relationship of thepair of guide plates GB. However, in the example shown in FIG. 8, it isnot possible to expose the reading side of the spectrophotometer CI andthe second background member BM2. For this reason, the example shown inFIG. 7 is preferable the example shown in FIG. 8.

Furthermore, in addition to the examples shown in FIG. 7 and FIG. 8, thepair of guide plates GB may be configured such that at least one of theupper guide plate GB1 and the lower guide plate GB2 can slidably movewhile maintaining parallel arrangement thereof. Also, the pair of guideplates GB may be configured such that only the lower guide plate GB2 canrotate, or that both the guide plates GB can rotate.

Referring to FIG. 3 and FIG. 4 again, in the structure as describedabove, the reading site of the scanner device SD and the reading site ofthe spectrophotometer CI is separated from each other by no greater thana predetermined distance in the direction along the paper conveyingroute PP. This structure can inhibit color variation due tothermochromism when reading colors with the scanner device SD and thespectrophotometer CI.

Next, the operation of the image reading apparatus 300 according to thepresent embodiment will be explained. First, a sheet P is introducedinto the image reading apparatus 300 from the image forming apparatus200. The sheet P is passed through the reading site of the scannerdevice SD and the reading site of the spectrophotometer CI anddischarged from the image reading apparatus 300 by driving the first tothird conveyance rollers R1 to R3.

When the motor M drives the first to third conveyance rollers R1 to R3,vibration is generated. However, since the motor M is mounted on thesupport base TR together with the paper conveying route PP and thespectrophotometer CI, the paper conveying route PP and thespectrophotometer CI are vibrated together so that it is easy tomaintain the positional relationship between the paper conveying routePP and the spectrophotometer CI. On the other hand, since the scannerdevice SD is fixed to the main body side, the vibration of the motor Mis hardly transmitted to the scanner device SD.

Particularly, since the vibration of the motor M is transmitted to thescanner device SD through the support base TR, the frame member FM andthe like, no large vibration is transmitted to the scanner device SD,which is thereby protected from vibrations.

On the other hand, it is assumed that a paper jam occurs on the firsttransfer route PP1. In this case, the first transfer route PP1 isexposed by pulling out the support base TR, and an operator can performjam handling. Furthermore, it is assumed that a paper jam occurs on thesecond transfer route PP2. In this case, an operator pulls out thesupport base TR, and operate the upper guide plate GB1 of the pair ofguide plates GB. The operator can thereby open the second transfer routePP2 and perform jam handling. This is true when performing maintenanceof the reading side of the spectrophotometer CI and the secondbackground member BM2.

In accordance with the image reading apparatus 300 and the image formingsystem 1 of the present embodiment, as has been discussed above, thescanner device SD is not mounted on the support base TR, but fixed tothe main body side. Because of this, the scanner device SD is separatedfrom the paper conveying route PP and the motor M for conveying a sheetP, and thereby hardly receives motor vibrations. On the other hand, thespectrophotometer CI is fixed to the support base TR in a positionspaced from the paper transfer route PP by a predetermined distance, andtherefore the spectrophotometer CI is integrated with the support baseTR having the paper conveying route PP. By this configuration, theposition accuracy of the spectrophotometer CI can be improved inrelation to the paper conveying route PP. Accordingly, in the case wherethere are provided a drawer-type structure in the form of the supportbase TR and a plurality of image reading units (the scanner device SDand the spectrophotometer CI), it is possible to optimize thearrangement of the plurality of image reading units.

On the other hand, the image reading apparatus 300 and the image formingsystem 1 are provided with the second background member BM2. Because ofthis, even if there is a substantial influence of a background onmeasurement when reading colors of a thin sheet P, it is possible toinhibit such an influence and contribute to stabilized colormeasurement. In addition to this, since the second background member BM2is mounted on the support base TR, it is possible to inhibit the secondbackground member BM2 from shifting.

Also, the pair of guide plates GB are configured in order that therelative positional relationship between the upper guide plate GB1 andthe lower guide plate GB2 can be changed, and that at least part of theinner surface IS of the pair of guide plates GB can be exposed. Becauseof this, since the inner surface IS of the pair of guide plates GB canbe exposed when the guide plates GB are moved, it is possible to reducethe possibility that, when the support base TR is pulled out, jamhandling on the second transfer route PP2 becomes difficult because ofthe presence of the spectrophotometer CI which is integrated with thesupport base TR.

Furthermore, the pair of guide plates GB are arranged to cover theoptical surface of the spectrophotometer CI and the second backgroundmember BM2. Because of this, when the support base TR is pulled out andthe pair of guide plates GB is not moved, the optical surface of thespectrophotometer CI is not exposed so that it can be protected. On theother hand, when maintenance of the optical surface of thespectrophotometer CI is to be performed, it is only required to pull outthe support base TR and move the pair of guide plates GB so that userconvenience can be improved.

Furthermore, the reading sites are separated from each other along thepaper conveying route PP within a predetermined distance. A sheet P ispassed through the first transfer route PP1, and immediately thereafterreaches the second transfer route PP2. Accordingly, it is possible toinhibit color variation due to thermochromism when reading colors withthe scanner device SD and the spectrophotometer CI respectively.

Also, the housing CH2 is arranged to be fitted into the hook-likeportion of the housing CH1. Because of this, it is possible to reduce awasted space and contribute to miniaturization. Particularly, in thecase of the scanner device SD consisting of the CCD line sensor SE andthe optical system such as the mirrors M1 to M5, a necessary light pathhas to be secured by the use of the mirrors M1 to M5. As compared with arectangular shape, therefore, the hook-type shape is suitable forsecuring the light path so that the system can be easily designed.

Furthermore, the support base TR is positioned by the first members E1which is provided on the frame member FM, and the scanner device SD isfixed by the second members E2 which is provided on the frame member FM.The relative position between the support base TR and the scanner deviceSD can thereby be appropriate through the frame member FM withoutdirectly connecting them for the purpose of making appropriate therelative position therebetween. In addition to this, vibration is hardlytransmitted to the scanner device SD from the motor M which is installedin the support base TR as compared with the case where the support baseTR and the scanner device SD are directly connected to each other inorder to determine the relative position therebetween.

The image reading apparatus and the image forming system have beenexplained based on the embodiment in accordance with the presentinvention. However, it is not intended to limit the present invention tothe precise form described, and obviously many modifications andvariations are possible without departing from the scope of theinvention. Also, if possible, the techniques of the embodiments can becombined as well as known techniques and the like.

For example, while the image reading apparatus 300 is independentlyinstalled in the case of the above embodiment, the present invention isnot limited to this installation, but the image reading apparatus 300can be incorporated in the image forming apparatus 200. Also in thiscase, there are similar advantages as in the above embodiment.

What is claimed is:
 1. An image reading apparatus comprising: a firstimage reading unit configured to sense a sheet conveyed on a paperconveying route and sense position, form, and color of an image formedon the sheet; a second image reading unit configured to sense color ofthe image formed on the sheet conveyed on the paper conveying route; asupport base which incorporates the paper conveying route and a motorfor conveying the sheet and can be pulled out from a main body togetherwith the paper conveying route and the motor, wherein the first imagereading unit is not mounted on the support base but fixed to a main bodyof the image reading apparatus, and wherein the second image readingunit is mounted on the support base and fixed to the support base in aposition spaced from the paper transfer route by a predetermineddistance.
 2. The image reading apparatus of claim 1 further comprising:a background member provided in a position opposite the second imagereading unit to provide a background when the second image reading unitsenses color, wherein the background member is fixed to the support basein the position.
 3. The image reading apparatus of claim 2 wherein thepaper conveying route includes a first transfer route on which isconveyed the sheet which is sensed by the first image reading unit and asecond transfer route on which is conveyed the sheet which is sensed bythe second image reading unit, wherein the second transfer route isprovided with a pair of guide plates which are arranged in parallel witheach other to guide conveyance of the sheet, wherein at least one of thepair of guide plates is configured to change the relative positionalrelationship to the other guide plate such that at least part of theinner surface of the pair of guide plates can be exposed.
 4. The imagereading apparatus of claim 3 wherein the pair of guide plates arearranged to cover a reading side of the second image reading unit andthe background member, and wherein at least one of the pair of guideplates is configured to change the relative positional relationship tothe other guide plate such that at least part of the inner surface ofthe pair of guide plates can be exposed, and that the optical surface ofthe second image reading unit and the background member can be exposed.5. The image reading apparatus of claim 3 wherein the reading sites ofthe first image reading unit and the second image reading unit areseparated from each other along the paper conveying route within apredetermined distance.
 6. The image reading apparatus of claim 1wherein the first image reading unit has a first housing which is formedinto an approximately hook-type shape as seen from the front side,wherein the second image reading unit has a second housing which isformed into an approximately rectangular shape as seen from the frontside, and the second housing in the form of the rectangular shape isarranged to be fitted into a hook-like portion of the first housing inthe form of the hook-type shape.
 7. The image reading apparatus of claim1 wherein the first image reading unit is a scanner device having a CCDline sensor and an optical system, and wherein the second image readingunit is a spectrophotometer.
 8. The image reading apparatus of claim 1wherein, when inserted into the main body, the support base ispositioned by a first member which is provided on a frame member formingthe main body, and wherein the first image reading unit is fixed to themain body through a second member which is provided on the frame member.9. An image forming apparatus which forms an image on a sheet andincorporates an image reading apparatus comprising: a first imagereading unit configured to sense a sheet conveyed on a paper conveyingroute and sense position, form, and color of an image formed on thesheet; a second image reading unit configured sense color of the imageformed on the sheet conveyed on the paper conveying route; a supportbase which incorporates the paper conveying route and a motor forconveying the sheet and can be pulled out from a main body together withthe paper conveying route and the motor, wherein the first image readingunit is not mounted on the support base but fixed to a main body of theimage reading apparatus, and wherein the second image reading unit ismounted on the support base and fixed to the support base in a positionspaced from the paper transfer route by a predetermined distance.
 10. Animage forming system including an image forming apparatus which forms animage on a sheet and an image reading apparatus comprising: a firstimage reading unit configured to sense a sheet conveyed on a paperconveying route and sense position, form, and color of an image formedon the sheet; a second image reading unit configured to sense color ofthe image formed on the sheet conveyed on the paper conveying route; asupport base which incorporates the paper conveying route and a motorfor conveying the sheet and can be pulled out from a main body togetherwith the paper conveying route and the motor, wherein the first imagereading unit is not mounted on the support base but fixed to a main bodyof the image reading apparatus, and wherein the second image readingunit is mounted on the support base and fixed to the support base in aposition spaced from the paper transfer route by a predetermineddistance.
 11. The image forming system of claim 10 wherein the imagereading apparatus further comprises a background member provided in aposition opposite the second image reading unit to provide a backgroundwhen the second image reading unit senses color, and wherein thebackground member is fixed to the support base in the position.
 12. Theimage forming system of claim 11 wherein the paper conveying routeincludes a first transfer route on which is conveyed the sheet which issensed by the first image reading unit and a second transfer route onwhich is conveyed the sheet which is sensed by the second image readingunit, wherein the second transfer route is provided with a pair of guideplates which are arranged in parallel with each other to guideconveyance of the sheet, wherein at least one of the pair of guideplates is configured to change the relative positional relationship tothe other guide plate such that at least part of the inner surface ofthe pair of guide plates can be exposed.
 13. The image forming system ofclaim 12 wherein the pair of guide plates are arranged to cover areading side of the second image reading unit and the background member,and wherein at least one of the pair of guide plates is configured tochange the relative positional relationship to the other guide platesuch that at least part of the inner surface of the pair of guide platescan be exposed, and that the optical surface of the second image readingunit and the background member can be exposed.
 14. The image formingsystem of claim 12 wherein the reading sites of the first image readingunit and the second image reading unit are separated from each otheralong the paper conveying route within a predetermined distance.
 15. Theimage forming system of claim 10 wherein the first image reading unithas a first housing which is formed into an approximately hook-typeshape as seen from the front side, wherein the second image reading unithas a second housing which is formed into an approximately rectangularshape as seen from the front side, and the second housing in the form ofthe rectangular shape is arranged to be fitted into a hook-like portionof the first housing in the form of the hook-type shape.
 16. The imageforming system of claim 10 wherein the first image reading unit is ascanner device having a CCD line sensor and an optical system, andwherein the second image reading unit is a spectrophotometer.
 17. Theimage forming system of claim 10 wherein, when inserted into the mainbody, the support base is positioned by a first member which is providedon a frame member forming the main body, and wherein the first imagereading unit is fixed to the main body through a second member which isprovided on the frame member.